Click here for recent reflections about what led to requiring "duct tape" to rescue Apollo 13.

The Testimony:

For
the Apollo 13 crew, the dilemma was that the square command ship’s CO2 filters
would not fit into the round rescue ship’s filter barrel.These had to work to clean the cabin
atmosphere of Carbon Dioxide gas.The
lander’sround filters were two in
number.Each had a life of
approximately 24 hours with two men on board.Since there were now three men,
that life would be somewhat shortened.The round filters were housed in two separate barrels in the
lander.One barrel was plumbed into the
cabin’s environmental control system.The other barrelsimply stowed
the second cartridge.When the first
filter was consumed, the crew simply interchanged the filters in the barrels.

At
the appointed time of Congress’s prayer edict, the first round filter would
need to be changed based on the 24 hour criteria.This would leave only 24 hours to deal with
the challenge and solve the problem of“making a square peg fit into a round hole.”Unfortunately, three more days journey would
be needed at that time to bring Apollo 13 home.This would be at least 48 hours short of the lander’s filters’
capacity.

My
recollection of the threat, besides the earlier meeting with Don Arabian, was
Don’s voice bellowing from his thronein the mission evaluation room that Tuesday,“I need those guys to come up with an answer on the CO2 thing!”He was referring to the “tiger team”led by Ed Smylie, the crew systems manager
working the problem.But, at 9:08 PM,
April 14, 1970, an explosion of prayer stormed heaven in behalf of Apollo 13. These intercessions had been requested earlier
that day by the a proclamation of the United State Congress.

Several
years later, I was speaking to a group of Christians in a small Texas community near Dallas.My topic was, of course, the impact of prayer on the rescue ofApollo 13.After the meeting, a woman asked to speak with me.She began,“Our church had been praying that week for Apollo 13.I recall something that was in my mind about
farmers trying to make pigs go into a barrel.It was difficult understanding what that had to do with Apollo 13, but I
prayed anyway that the farmers would succeed.”

I
responded,“What you remember is exactly
what we faced that evening…it had to do with a square ‘pig’filter not fitting into a round barrel.Our engineers were your farmers, those pigs
were the square command ship’s carbon dioxide filters, and the barrel would be
the cylinder containing the round CO2 filters in the rescue ship.”I
believe Congress’ proclamation led to such a “vision” and prayer.The team benefited from that prayer.In a back room atthe MannedSpacecraftCenter, they assembled a barn yard of space components, items
known to be onboard Apollo 13:Moon rock
plastic bags, suit hoses, card board checklist covers and bungee cords.With the square filters, these were
components which might comprise a “witty invention” capable ofmaking those square filters work in the round
barrel system.

The
Bible speaks of God knowing the number of hairs on our heads.The average number of hair follicles at any
one time on a person is 100,000. Each hair follicles can grow about 20 hairs in
a person’s lifetime.So God knows about
2,000,000of our hairs.Now the number of parts in the command module
was about 2,000,000.Isn’t it reasonable
to conclude that God knows each of those parts as well as our hairs. But He
cares much more about the men on board than their hair so that He can impart wisdom to fix any of
those millions of parts to make that filtering system work.

While
the nation prayed,Smylie and his team
conceived a configuration that might be successful.The concept seemed to evolve as all looked
on.It was to attach a suit hose into a
port which blew air through the hose into an astronaut’s space suit.If the space suit was eliminated and,
instead, the output of the hose somehow attached to the square filter,perhaps, the crew could be saved.This, in effect, would bypass the
barrel.The air blown through the
filter by the suit fan would have no carbon dioxide as it reentered the cabin
atmosphere.

The
challenge was attaching the hose into a funnel-like device having a small round
inlet hole for the suit hose and a much larger square outlet attached and
surrounding the square filter.But the
funnel would most likely leak.Added to
that difficulty was the hose and plastic Moon bags tended to collapse
restricting the air flow through the filter.The thought came, “Use cardboard log book covers to support the
plastic.” It worked!But more
importantly, “How could the funnel be fashioned to prevent leaking?”Of course…the solution to every conceivable
knotty problem has got to be…DUCT TAPE!And so it was.Someone,providentially, had stowed the miracle
substance onboard.

Using
the plastic Moon rock bags, cardboard, suit hoses, andduct tape, the device was attached to that
filter.Soon the CO2 levels had
descended to safe levels.God had made
a way of fitting a square peg into a round hole because the nation prayed that
Tuesday evening in April of 1970. When theMaster Engineer of the Universe, the Lord Jesus Christ, was called as a
problem solver, He never fails.Having
read my account, try the exercise described below.Of course, it would be good to pray first for
God’s help.In this way, you will
understand how very helpful He was to save our astronauts that week in April of
1970.

* * * * * * * * * *

Apollo 13 Rescue Exercise

Requires Adult Supervision

“Making a Square Peg Fit into a Round
Hole”

The YouTube demonstration is much superior to the exercise posted below which I created years ago. Watch the
video and collect the materials described in it for your class. (Note: The hair blower would work well with the vacuum cleaner
hose rather than using a handheld vacuum cleaner. Of course, the cold air setting should be selected on the hair blower.
Also, the simulated square CO2 filter in the video was constructed from a one foot square AC filter bought at a grocery store. By
cutting it into four square pieces and stacking them using, of course, duct tape or masking tape to hold the stack together, I fashioned the
demonstration Apollo 13 square CO2 filter. )

Click here for a YouTube clip from one of the SKYPE shows which includes Jerry's demonstation constructing the Apollo 13 CO2 filter
apparatus using DUCT TAPE that saved the crew from death. (The above photo is from the show.)

The following exercise is not nearly as good as the demonstration I put on YouTube.

Click here to watch a video of the Apollo 13 crew assembling the modified
CO2 filter using duct tape.

8 ½” by 11” card stock,cloth fabric, roll of garden weed
mesh, discarded shoe (or any other similar) box,discarded garden hose, scissors.All the items (except for garden mesh, hose
and box) are likely available at a hardware or grocery store. Hand held hair
dryers are always available at home.

Left Photo of First
Built Version of Filter, Right Photois
Astronaut upgrade

Instructions:

Examine the above photos for clues about fashioning
your version of the Apollo 13 “jury-rig” filter from the list of
materials.

Read the air-ground instructions given the Apollo 13
astronauts for added information about making your filter.They
are listed below.

Using the instructions, pictures, and materials build
a square filter with a configuration which plumbs air from the blow dryer
through the hose and ultimately the filter without leaking.

DANGER:BE CAREFUL

ATTENTION: Be sure to select the warm rather
than hot setting for the blower when you switch on the hair dryer.Use your hand to test whether your
design and finished approach is “air-tight”.

Examine the photos above.What improvement is evident in the
photo at the right of the improved version made by the Apollo 13 crew? The
left photo shows the original version built by the crew from the instructions
radioed by mission control, then constructed by the astronauts.

For the Instructor:

The
sides of the shoe (or similar) box serve as the frame/structure of the
filter.Cut out the center bottom of
the show box after removing the shoe box lid.Cut the plastic weed screen to cover the topopen end of the shoe box, then attach the
mesh using masking tape around the top of the shoe box holding the mesh taunt and taping the mesh to the sides of the box as you might wrap a gift.[The mesh serves as the filtering
material.Explain to the students the
principle involved, i.e., having contaminated air pass through the fine mesh as
though it is LiOH crystals for removing CO2 from the cabin atmosphere.Explain the purpose of the blower being a
substitute for the Apollo 13 suit fan.]

Have
the students construct both the square filter as well as the modified
apparatus. Their device would have enabled the Apollo 13 crew to avoid using
the round lander filters in the barrel-like containers shown in the above right
photo.

Also,
have the students fashion the means for conducting the dryer’s air flow through
the garden hose into their filter system. [Prior to class, you will need to cut
the garden hose into one – two foot lengths.] Note the version the ground controllers built
and the later improved version built by the Apollo 13 astronauts differ.Likewise, will student’s designs and finished
products differ.Have a selected team of
students evaluate the completed devices and give reasons for strengths and
weaknesses of each.

Lastly:Simply provide this description of the
activity to the students and have them draw, explain, or write a narrative
description of how to build their square filter apparatus without actually
constructing it.Let them pretend they
are mission control instructing the Apollo 13 crew via radio in a step-by-step
procedures how it is done. Then, ask a separate team of students to copy down
the instructions and attempt to assemble (draw) the filter as did the Apollo 13
astronauts without having a picture or photo of it. (This is certainly the least involved of the approaches.No materials required other than imagination
and ingenuity.)

* * * * * * * * * *

The educational activity supporting the above exercise follows.It is simply a close approximation of the
air-to-ground procedures called up to the crew in April of 1970. It was created
from the original Apollo 13 radio communication for a college class assignment
in Communications by George Wilson, COMM
4120, Assignment #3, 13 May 2004.This was an exercise in communicating
Instructions and Procedures.

Adaptation Procedure

for

Environmental System CO2 Filters

in

Apollo 13 Lunar Module

INTRODUCTION

This procedure, which takes approximately one hour to
complete, will allow the fitting of a square Odyssey Command Module (CM)
scrubber filter through the Aquarius Lunar Module’s (LM) round mounted
filtration hole and will modify the Environmental Systems scrubber unit. The
material is for astronauts to use when CO2 scrubbers fail in the CM,
all CM filters are used or in other situations where additional scrubbing of CO2
is required. Crew Systems Division assembled and tested this information.

REQUIRED EQUIPMENT
and MATERIALS

All required equipment is contained onboard within the
Apollo 13 CM and LM.

1 bungee cord (to secure the
modified filtration device to the wall of the LM)

PROCEEDURE - 19
steps

#1) Place the LCG
bag over the top of the square lithium-hydroxide canister. The bag must be pulled down to just over the triangular
ventilator slots on the side.

NOTE:Be
careful not to rip the bag because there are only three bags onboard.

#2) Tear the duct tape down the middle lengthwise to double
the linear length.

#3) Seal the bag
to the square canister by wrapping the
duct tape around the canister where the bag opening is.

NOTE:The tape must seal the opening
to prevent leakage of air flow.

#4) Poke or cut a
hole in the middle of the top of the covering bag approximately the diameter of the hose from the red suit.

#5) Insert the
hose into the hole. Secure the hose
connection into the LCG bag with duct tape.

NOTE:The tape must seal the opening
to prevent leakage of air flow.

#6) Cover the top
of the LCG bag and hose attachment with the flight plan cover in an arch. The hose will stick out of one side of the
arch.

#7) Attach the two
sides of the cardboard flight plan cover
that make contact with the square filter using a six inch long piece of duct
tape over the top. This will prevent crushing the hose and air entry on the final
mounting in step #19.

#8) Wrap the
entire top sides of the filter cube with a three foot (about an arms length) piece
of duct tape. Repeat wrapping on the
bottom of the sides of the cube.

NOTE:The tape must seal the opening
to prevent leakage of air flow.

#9) Secure the
bag with strips of duct tape two per side
running from one side, under the bottom and back up the other side. Repeat on
the other side. The bottom of the cube will resemble a tic tac toe board when
this step is completed. (See Figure 1 to the right)

Figure 1

#10) Stuff the
sock into the ventration hole in the
center of the square scrubber. This will prevent the air from bypassing the
filter. Cover the hole with a couple of pieces of tape to keep it from falling
out.

#11) Repeat steps
#3 through #10 for the second canister.
This will be the replacement when the first filter becomes saturated.

#12) Open the
sensor relief valve. This will normalize
the pressure and allow you to attach the hose to the intake valve.

#13) Attach the
free end of the hose to the scrubber intake.

#14) Attach the end of the bungee cord to
the hook above the lithium canister mounting location on the bulkhead. (See
Figure 1 in step #9 above)

#15) Secure the canister to the bulkhead
by hooking the other end of the bungee cord below the mounting location. (See
figure 1 in step #9 above)

#16) Attach the crossover hose to the
secondary air cleaner.

#17) Close the sensor relief valve
opened in step 12.

#18) Set the CO2 select to
secondary using the LM air cleaner selection switch on panel eleven.

#19) Engage the air cleaning scrubber fan
by flipping the ACSF switch located on panel eleven.

VERIFICATION

Check the CO2 levels on the partial
pressure (marked PART PRES C02) meter on panel eleven. The level should begin
to fall (safe level of partial pressure
is below eight (8)). Further verification will be indicated through the
amber CO2 warning light set to illuminate if the level is above ten
(10).

If the canister seals are not correct in steps
#3, #5 and #8, CO2 cleaning may not be adequate. You will recognize
this if you hear a whooshing sound when the system starts. Re-tape the seal
that is leaking.

If the LCG bags get ripped air flow may leak
out and fail to clean the CO2. Use the spare bag if this happens.